Production schedule for a automotive motor head manufacturing
plant Anirudh Jagannathan aj2560 Jorge Ortiz jeo2130 Yanira
Pichardo yp2323
Slide 2
Problem description The plant we will be studying is Nemaks
Plant #4 in their Monterrey site, focusing on their core blowing
operation. A consultancy project took place back in 2010, with one
of the deliverables being an Excel workbook with macros that
automated the creation of each weeks production schedule. The
production schedule workbook delivered back then was done in such a
way as to try and meet the production deadlines as much and as well
as possible( L max ) and try and make each machine finish around
the same time, having the minimum amount of downtime as possible (
C max ).
Slide 3
Process diagram Milling Core blowing Motor head molding
Cleaning De- burring Packaging for shipping SandResinAluminum Core
assembly Destroyed cores Excess aluminum Motor head
Slide 4
Project objective We want to determine the following: 1.Was the
production schedule proposed back in 2010 optimal or not ( C max, L
max ) 2.How we could improve it. 3.How far from optimal was it.
Stretch goal 1.Figure out if the way the Excel macro was programmed
(running time) was efficient or not, going into Big O
notation.
Slide 5
Problem complexity 1.The plant has 21 core blower machines.
2.Production requirements for the following week arrive each
Thursday morning and are detailed on a daily basis (daily due
dates). 3.Plant managers can set priorities to each product that is
in the production requirements for the week. (weights for each job)
4.Each core blower can blow certain types of cores for each
product. 5.Each core blower can work with only a certain set of
toolings. 6.Each product is made up of multiple cores and there are
cores that form part of more than one type of product. 7.We have
information regarding core blower machines and tooling
availabilities for each week (sometimes either machines or tooling
are undergoing preventive or corrective maintenance). 8.We have
information regarding the current state of the inventory and in
some cases, for some products, there is a produce up to level.
Slide 6
Scope delimitation The Excel workbook is complex and has many
functionalities, however for this project we will only focus on the
following: Functionalities Product requirement by day (due dates)
Prioritization of product requirements Machines available hours
Tooling-Machine compatibility Tooling availability Setup times
Scrap percentages OEE (Overall Equipment Effectiveness) Cores
(Build of materials for each product) Initial inventory Detailed
production schedule Summarized production schedule Daily schedule
by machine graph Machines hours in use for the week graph
Unallocated remaining production hours Functionalities Milling
capacity Sand requirements (raw materials) SAP / historical data
Carts (to transport the finished cores) Milling used capacity graph
Unallocated remaining production hours The following
functionalities were dropped from our analysis:
Slide 7
General macro logic 1.Daily turntable requirements 2.Product
prioritization 3.Machine availability 4.Tooling availability
5.Initial inventory (automatically pulled by the macro) 6.Build of
materials for each product 1.Sort the products using the
prioritization list. 2.Consult the products build of materials.
3.Consult the initial inventory. 4.Determine if the core being
analyzed is in stock or it has to be produced. 5.If the product has
to be produced, allocate an available tooling. 6.Allocate to the
first available machine that is compatible with this tooling. 7.Go
to the next core of that product until you finish its build of
materials. 8.Go to the next product down the prioritization list
until you finish with the whole requirements list, or you run out
of available machine-hours in the day. 1.Detailed production
schedule 2.Summarized production schedule 3.Graphs INPUTS PROCESS
OUTPUTS
Slide 8
Current scheduling
Slide 9
Slide 10
By using the wrap-around rule theres risk that if a machine
breakdown occurs (specially late during the day), you might be
unable to fulfill your orders because you are missing one or more
of the cores required to assemble a specific product. J 2 J 3 J 2
t=Dt=0 J 1 M1 M2 M3
Slide 11
Proposed scheduling By using an alternative scheduling
algorithm, where a job is assigned to each machine and once all
machines have a job assigned to them you assign a second job and so
on, you can reduce the aforementioned risk, reduce the makespan,
and balance your operations (little or no idle time in machines). J
2 J 3 t=Dt=0 J 1 M1 M2 M3 t=D
